[skip ci] part Qt embedding test application to Py3 and implement workaround for Qt5

src/Tools/embedded/Qt/Qt.pro

@@ -1,12 +1,26 @@
-######################################################################
-# Automatically generated by qmake (2.01a) Di 15. Mrz 12:13:51 2011
-######################################################################
-
-TEMPLATE = app
-TARGET = 
-DEPENDPATH += .
-INCLUDEPATH += .
-
-# Input
-HEADERS += mainwindow.h
-SOURCES += main.cpp mainwindow.cpp
+
+TEMPLATE = app
+TARGET = Qt
+INCLUDEPATH += .
+
+linux {
+  INCLUDEPATH += /usr/include/python3.6
+  LIBS += -lpython3.6m
+}
+
+QT += widgets
+
+# The following define makes your compiler warn you if you use any
+# feature of Qt which has been marked as deprecated (the exact warnings
+# depend on your compiler). Please consult the documentation of the
+# deprecated API in order to know how to port your code away from it.
+DEFINES += QT_DEPRECATED_WARNINGS
+
+# You can also make your code fail to compile if you use deprecated APIs.
+# In order to do so, uncomment the following line.
+# You can also select to disable deprecated APIs only up to a certain version of Qt.
+#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0
+
+# Input
+HEADERS += mainwindow.h
+SOURCES += main.cpp mainwindow.cpp

src/Tools/embedded/Qt/main.cpp

@@ -1,15 +1,21 @@
 
-#include <Python.h>
+#include <Python.h>
 #include <QApplication>
 
 #include "mainwindow.h"
 
 int main(int argc, char *argv[])
 {
-    char* name = "Qt example";
-    Py_SetProgramName(name);
+    const char* name = "Qt example";
+    Py_SetProgramName(Py_DecodeLocale(name,NULL));
     Py_Initialize();
-    PySys_SetArgv(argc, argv);
+
+    size_t size = argc;
+    wchar_t **_argv = new wchar_t*[size];
+    for (int i = 0; i < argc; i++) {
+        _argv[i] = Py_DecodeLocale(argv[i],NULL);
+    }
+    PySys_SetArgv(argc, _argv);
 
     QApplication app(argc, argv);
     MainWindow mainWin;

src/Tools/embedded/Qt/mainwindow.cpp

@@ -3,6 +3,7 @@
 #include <string>
 #include <sstream>
 #include <QtGui>
+#include <QtWidgets>
 #if defined(Q_WS_X11)
 # include <QX11EmbedContainer>
 #endif
@@ -87,7 +88,7 @@ void MainWindow::loadFreeCAD()
             PyObject *ptype, *pvalue, *ptrace;
             PyErr_Fetch(&ptype, &pvalue, &ptrace);
             PyObject* pystring = PyObject_Str(pvalue);
-            const char* error = PyString_AsString(pystring);
+            const char* error = PyUnicode_AsUTF8(pystring);
             QMessageBox::warning(this, "Error", error);
             Py_DECREF(pystring);
         }
@@ -110,7 +111,7 @@ void MainWindow::newDocument()
         PyObject *ptype, *pvalue, *ptrace;
         PyErr_Fetch(&ptype, &pvalue, &ptrace);
         PyObject* pystring = PyObject_Str(pvalue);
-        const char* error = PyString_AsString(pystring);
+        const char* error = PyUnicode_AsUTF8(pystring);
         QMessageBox::warning(this, "Error", error);
         Py_DECREF(pystring);
     }
@@ -119,7 +120,6 @@ void MainWindow::newDocument()
 
 void MainWindow::embedWindow()
 {
-    WId hwnd = this->centralWidget()->winId();
     PyObject* main = PyImport_AddModule("__main__");
     PyObject* dict = PyModule_GetDict(main);
     std::stringstream cmd;
@@ -134,18 +134,41 @@ void MainWindow::embedWindow()
         << "\n"
         << "FreeCADGui.addWorkbench(BlankWorkbench)\n"
         << "FreeCADGui.activateWorkbench(\"BlankWorkbench\")\n"
-        << "FreeCADGui.embedToWindow(\"" << hwnd << "\")\n"
         << "\n";
+
+#if defined(Q_WS_X11) || defined(Q_OS_WIN)
+    WId hwnd = this->centralWidget()->winId();
+    cmd << "FreeCADGui.embedToWindow(\"" << hwnd << "\")\n"
+        << "\n";
+#endif
+
     PyObject* result = PyRun_String(cmd.str().c_str(), Py_file_input, dict, dict);
     if (result) {
         Py_DECREF(result);
+
+#if !defined(Q_WS_X11)
+        // This is a workaround for the lack of a replacement of QX11EmbedWidget with Qt5
+        QWidget* mw = nullptr;
+        for (auto it : qApp->topLevelWidgets()) {
+            if (it->inherits("Gui::MainWindow")) {
+              mw = it;
+              break;
+            }
+        }
+        if (mw) {
+            QVBoxLayout* vb = new QVBoxLayout();
+            centralWidget()->setLayout(vb);
+            vb->addWidget(mw);
+        }
+#endif
+
         embedAct->setDisabled(true);
     }
     else {
         PyObject *ptype, *pvalue, *ptrace;
         PyErr_Fetch(&ptype, &pvalue, &ptrace);
         PyObject* pystring = PyObject_Str(pvalue);
-        const char* error = PyString_AsString(pystring);
+        const char* error = PyUnicode_AsUTF8(pystring);
         QMessageBox::warning(this, "Error", error);
         Py_DECREF(pystring);
     }